A wireless charging device (system) can deliver energy wirelessly to a load without a transmission line by converting electric energy to electromagnetic waves.
A magnetic induction scheme as one of wireless charging schemes uses a magnetic field induced from a coil to deliver power, and can provide energy to a load in such a manner that induction current is allowed to flow in a reception coil by using a magnetic field generated from current that flows in a transmission coil. A standard of the magnetic induction scheme includes wireless power consortium (WPC), power matters alliance (PMA), or the like. A power transmission frequency may use 110-205 kHz in case of the WPC, and may use 227-357 kHz and 118-153 kHz in case of the PMA.
Charging power of the wireless charging system is variable depending on a load condition and charging current which are set in the system, whereas charging voltage can be used statically. With the quick charging and high-power wireless charging in the wireless charging system, heat generation is increased, which may cause a usage restriction.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.